Tool Height Tolerance

[epanzella]

I know cutting tools are usually set on center but I wonder what the tolerance is? .0001" .001" .010"? All I ever see is "as close as possible", but what's possible can change with finer fixtures and better techniques. I currently use the standing straightedge procedure. Is this good enough? How far should I chase this thing?

 

[Ulma Doctor]

it has a lot to do with what you are machining and what you are making and whether you are turning or facing, or parting.
if you were within .001" that would be ideal
you can chase tenths but it's really not necessary for the stuff we are likely to construct

 

[Tozguy]

I kinda like to error slightly on the high side as a hedge against deflection and flex in the system between ways and tool.
An adjustable gauge can be set very accurately and makes easy work of setting a QCTP in the 0 to +.0005'' range.

 

[mikey]

I use mostly HSS tooling that cuts best when set on centerline so I use a simple height gauge that is on the exact centerline of my spindle. Similar in concept to @Tozguy. When I use inserted carbide, I use the same gauge but try to remember to adjust the tool holder about 0.005 high. This is to accommodate tangential cutting forces and it works rather well. The harder the material and the deeper my depth of cut, the more important this becomes. You might give it a try.

 

[Wreck™Wreck]

I kinda like to error slightly on the high side as a hedge against deflection and flex in the system between ways and tool.
An adjustable gauge can be set very accurately and makes easy work of setting a QCTP in the 0 to +.0005'' range.

Surely you jest.

 

[Ray C]

No matter what tooling is in use (carbide or HSS) I do a face cut and adjust height until the the little dimple in the center cuts off nicely. Tool holders have a locknut to preserve the height and I snug that enough so it won't change during normal handling. Since I use mainly carbide inserts, some of those tool holder were probably last adjusted 5 or more years ago.

Ray C

 

[Fabrickator]

I use a mag base digital height gauge and follow-up with the "dimple cut-off" method. I think I bought mine off of Grizzly, but they're sold all over.

https://www.googleadservices.com/pa...hUKEwiYgMXGqvPYAhWNyKQKHfcaCvcQ9aACCDc&adurl=

 

[Tozguy]

Surely you jest.

I knew someone would pick me up on this. Not really jesting but it is a calculation and not an actual measurement.

 

[chips&more]

I just eye ball it. Have been all my life, never had a problem. IMHO it’s not a big deal. I do take the time to better align things if I’m facing and don’t what that little tit.

 

[Rooster]

I chucked up a piece of 3/4" round brass and with a very sharp HSS tool faced it until i got the tool on dead center. Then i bored the end for a 1/2" X 1/8" rare earth magnet which i epoxied in. I then placed it on the ways and using the same tool scribed a line at the correct height, then re-chucked it and faced it too dead center length. It is very easy too set a tool height by feel or sight